Costa Rica Guided Tours: Are They Necessary, Valuable, And/Or Worthwhile?

Hello folks,
I have been in Costa Rica a couple of times, well, maybe more, the first time I believed I could do and find anything since is such a little country, that ocassion I missed a lot because that place is a Pandora´s Box and you have to have trained eye or ear to see the most posible and that of course we are not for a while, then I felt in love with birdwatching and decided to hire a guide, not only a nice person with whom to share a slow and nice hike but also with that trained habilities I didn´t have, he showed me so many species, not only birds and his service was appreciated, also worthy 100%. Maybe not in every place, but the most hiden parks or reserves I would say Yes, hire a guide in Costa Rica.

I understand the value of the guided tours, but I need to juggle that with my two son’s need to explore and really feel like they are not on the beaten path. Any recommendations. The ages of my boys are 22 and 18, in great shape and they will want a butt kicking hike and I don’t think a guide is necessary for this. For the rapelling, and rafting yes, but I don’t think they will listen to 6 days of guides, Any suggestions as to hikes that can be done on our own, or possible with a guide. I don’t know! So many options, so little time! 🙂